/*
   * Copyright (c) 2009 Oracle.  All rights reserved.
   *
   * This software is available to you under a choice of one of two
   * licenses.  You may choose to be licensed under the terms of the GNU
   * General Public License (GPL) Version 2, available from the file
   * COPYING in the main directory of this source tree, or the
   * OpenIB.org BSD license below:
   *
   *     Redistribution and use in source and binary forms, with or
   *     without modification, are permitted provided that the following
   *     conditions are met:
   *
   *      - Redistributions of source code must retain the above
   *        copyright notice, this list of conditions and the following
   *        disclaimer.
   *
   *      - Redistributions in binary form must reproduce the above
   *        copyright notice, this list of conditions and the following
   *        disclaimer in the documentation and/or other materials
   *        provided with the distribution.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
   * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
   * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   *
   */

  #include <linux/module.h>

  #include <rdma/rdma_cm.h>
  
  #include "rdma_transport.h"

  static struct rdma_cm_id *rds_rdma_listen_id;

  static char *rds_cm_event_strings[] = {
  #define RDS_CM_EVENT_STRING(foo) \
  		[RDMA_CM_EVENT_##foo] = __stringify(RDMA_CM_EVENT_##foo)
  	RDS_CM_EVENT_STRING(ADDR_RESOLVED),
  	RDS_CM_EVENT_STRING(ADDR_ERROR),
  	RDS_CM_EVENT_STRING(ROUTE_RESOLVED),
  	RDS_CM_EVENT_STRING(ROUTE_ERROR),
  	RDS_CM_EVENT_STRING(CONNECT_REQUEST),
  	RDS_CM_EVENT_STRING(CONNECT_RESPONSE),
  	RDS_CM_EVENT_STRING(CONNECT_ERROR),
  	RDS_CM_EVENT_STRING(UNREACHABLE),
  	RDS_CM_EVENT_STRING(REJECTED),
  	RDS_CM_EVENT_STRING(ESTABLISHED),
  	RDS_CM_EVENT_STRING(DISCONNECTED),
  	RDS_CM_EVENT_STRING(DEVICE_REMOVAL),
  	RDS_CM_EVENT_STRING(MULTICAST_JOIN),
  	RDS_CM_EVENT_STRING(MULTICAST_ERROR),
  	RDS_CM_EVENT_STRING(ADDR_CHANGE),
  	RDS_CM_EVENT_STRING(TIMEWAIT_EXIT),
  #undef RDS_CM_EVENT_STRING
  };
  
  static char *rds_cm_event_str(enum rdma_cm_event_type type)
  {
  	return rds_str_array(rds_cm_event_strings,
  			     ARRAY_SIZE(rds_cm_event_strings), type);
  };

  int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
  			      struct rdma_cm_event *event)
  {
  	/* this can be null in the listening path */
  	struct rds_connection *conn = cm_id->context;
  	struct rds_transport *trans;
  	int ret = 0;

  	rdsdebug("conn %p id %p handling event %u (%s)
  ", conn, cm_id,
  		 event->event, rds_cm_event_str(event->event));

  
  	if (cm_id->device->node_type == RDMA_NODE_RNIC)
  		trans = &rds_iw_transport;
  	else
  		trans = &rds_ib_transport;
  
  	/* Prevent shutdown from tearing down the connection
  	 * while we're executing. */
  	if (conn) {
  		mutex_lock(&conn->c_cm_lock);
  
  		/* If the connection is being shut down, bail out
  		 * right away. We return 0 so cm_id doesn't get
  		 * destroyed prematurely */
  		if (rds_conn_state(conn) == RDS_CONN_DISCONNECTING) {
  			/* Reject incoming connections while we're tearing
  			 * down an existing one. */
  			if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST)
  				ret = 1;
  			goto out;
  		}
  	}
  
  	switch (event->event) {
  	case RDMA_CM_EVENT_CONNECT_REQUEST:
  		ret = trans->cm_handle_connect(cm_id, event);
  		break;
  
  	case RDMA_CM_EVENT_ADDR_RESOLVED:
  		/* XXX do we need to clean up if this fails? */
  		ret = rdma_resolve_route(cm_id,
  					 RDS_RDMA_RESOLVE_TIMEOUT_MS);
  		break;
  
  	case RDMA_CM_EVENT_ROUTE_RESOLVED:
  		/* XXX worry about racing with listen acceptance */
  		ret = trans->cm_initiate_connect(cm_id);
  		break;
  
  	case RDMA_CM_EVENT_ESTABLISHED:
  		trans->cm_connect_complete(conn, event);
  		break;
  
  	case RDMA_CM_EVENT_ADDR_ERROR:
  	case RDMA_CM_EVENT_ROUTE_ERROR:
  	case RDMA_CM_EVENT_CONNECT_ERROR:
  	case RDMA_CM_EVENT_UNREACHABLE:
  	case RDMA_CM_EVENT_REJECTED:
  	case RDMA_CM_EVENT_DEVICE_REMOVAL:
  	case RDMA_CM_EVENT_ADDR_CHANGE:
  		if (conn)
  			rds_conn_drop(conn);
  		break;
  
  	case RDMA_CM_EVENT_DISCONNECTED:

  		rdsdebug("DISCONNECT event - dropping connection "

  			"%pI4->%pI4
  ", &conn->c_laddr,
  			 &conn->c_faddr);
  		rds_conn_drop(conn);
  		break;
  
  	default:
  		/* things like device disconnect? */

  		printk(KERN_ERR "RDS: unknown event %u (%s)!
  ",
  		       event->event, rds_cm_event_str(event->event));

  		break;
  	}
  
  out:
  	if (conn)
  		mutex_unlock(&conn->c_cm_lock);

  	rdsdebug("id %p event %u (%s) handling ret %d
  ", cm_id, event->event,
  		 rds_cm_event_str(event->event), ret);

  
  	return ret;
  }

  static int rds_rdma_listen_init(void)

  {
  	struct sockaddr_in sin;
  	struct rdma_cm_id *cm_id;
  	int ret;

  	cm_id = rdma_create_id(rds_rdma_cm_event_handler, NULL, RDMA_PS_TCP,
  			       IB_QPT_RC);

  	if (IS_ERR(cm_id)) {
  		ret = PTR_ERR(cm_id);

  		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "

  		       "rdma_create_id() returned %d
  ", ret);

  		return ret;

  	}

  	sin.sin_family = AF_INET,

  	sin.sin_addr.s_addr = (__force u32)htonl(INADDR_ANY);
  	sin.sin_port = (__force u16)htons(RDS_PORT);
  
  	/*
  	 * XXX I bet this binds the cm_id to a device.  If we want to support
  	 * fail-over we'll have to take this into consideration.
  	 */
  	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&sin);
  	if (ret) {

  		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "

  		       "rdma_bind_addr() returned %d
  ", ret);
  		goto out;
  	}
  
  	ret = rdma_listen(cm_id, 128);
  	if (ret) {

  		printk(KERN_ERR "RDS/RDMA: failed to setup listener, "

  		       "rdma_listen() returned %d
  ", ret);
  		goto out;
  	}
  
  	rdsdebug("cm %p listening on port %u
  ", cm_id, RDS_PORT);

  	rds_rdma_listen_id = cm_id;

  	cm_id = NULL;
  out:
  	if (cm_id)
  		rdma_destroy_id(cm_id);
  	return ret;
  }
  
  static void rds_rdma_listen_stop(void)
  {

  	if (rds_rdma_listen_id) {
  		rdsdebug("cm %p
  ", rds_rdma_listen_id);
  		rdma_destroy_id(rds_rdma_listen_id);
  		rds_rdma_listen_id = NULL;

  	}
  }

  static int rds_rdma_init(void)

  {
  	int ret;
  
  	ret = rds_rdma_listen_init();
  	if (ret)
  		goto out;
  
  	ret = rds_iw_init();
  	if (ret)
  		goto err_iw_init;
  
  	ret = rds_ib_init();
  	if (ret)
  		goto err_ib_init;
  
  	goto out;
  
  err_ib_init:
  	rds_iw_exit();
  err_iw_init:
  	rds_rdma_listen_stop();
  out:
  	return ret;
  }

  module_init(rds_rdma_init);

  static void rds_rdma_exit(void)

  {
  	/* stop listening first to ensure no new connections are attempted */
  	rds_rdma_listen_stop();
  	rds_ib_exit();
  	rds_iw_exit();
  }

  module_exit(rds_rdma_exit);
  
  MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
  MODULE_DESCRIPTION("RDS: IB/iWARP transport");
  MODULE_LICENSE("Dual BSD/GPL");